Mercalli earthquake response

Flooding and earthquakes, their brief characteristics are studied back in school. In the lessons, children are also told about how to behave when these phenomena occur. School discipline, which describes the characteristics of earthquakes - life safety . This subject is of practical importance, as it provides a basic understanding of natural disasters. Let us further consider what constitutes an earthquake. Offensive time and key features will also be described in the article.

Definition

It contains a brief description of the earthquake . Under it is understood underground vibrations and surface shocks, provoked mainly by natural and (to a lesser extent) artificial factors. The first, in particular, include mainly tectonic processes. Artificial factors include reservoir fillings, explosions, collapse of mine workings , etc. Small shocks are also a consequence of the rise of lava during a volcanic eruption. A brief description of the earthquake, therefore, indicates that it is a natural phenomenon. It can be caused by various factors.

General characteristics of earthquakes

Every year about a million vibrations and tremors occur on the planet. However, most of them are so insignificant that they go unnoticed. Strong earthquakes, resulting in extensive destruction, occur on the planet approximately every 2 weeks. Most of them happen at the bottom of the oceans, so it does not cause catastrophic consequences (if they do not provoke a tsunami). Shock strength is a key characteristic of earthquakes. In Russia and abroad, experts acknowledge that at present there is no single methodology that allows with sufficient probability to predict specific signs of these natural phenomena and their consequences. Moreover, experts note that it is unlikely to be developed in the foreseeable future. Knowing the causes and characteristics of earthquakes , there is currently no way to predict them.

Mechanism of occurrence

The main characteristics of earthquakes are determined by the catastrophic devastations that they can cause. The destruction of structures is provoked by fluctuations in the soil or tsunamis (giant waves). The latter are determined by seismic displacements of the bottom. Most of the foci occur at the surface of the earth. Shocks and vibrations occur when the crust is displaced as a whole layer, provoked by the elastic deformation of stressed rocks.

Seismic waves

They are divided into 2 categories. The first includes compression waves or longitudinal. They provoke fluctuations in the particles of rocks through which they pass, along the path of their distribution. This causes the alternation of rarefaction and compression sites in the rocks. These waves are recorded first, due to their high speed. They are also called primary (P-waves). At a frequency of more than 15 Hz, they can be perceived by ear as an underground rumble and hum. Shear waves (transverse, S waves) cause perpendicular vibrations of particles in the rocks. They are called secondary.

Medical and tactical characteristics of lesions during earthquakes

In the area of ​​direct vibrations and shocks, the following is noted:

1. The destruction of residential buildings, industrial buildings, medical institutions including. A large number of people who have received injuries of a combined type are located and die under their debris.
2. Blockages and destruction of settlements, highways as a result of the formation of extensive and numerous cracks in the crust, landslides, landslides.
3. Massive fires and explosions. They arise due to industrial accidents and short circuits in power networks.
4. Flooding as a result of numerous debris and dam on the rivers.
5. Loss of control over radiation sources AOKHV, etc.
6. The psychological impact on citizens, leading to severe nervous disorders, in some cases fatal.

Mandatory events

The medico-tactical characteristic of earthquakes allows us to develop a set of work that needs to be done. Mandatory events include:

1. Removing citizens from the rubble, from buildings covered by fires.
2. Localization and elimination of disasters and accidents on technological and utility lines threatening the life of the population.
3. Strengthening or collapse of structures in emergency condition.
4. Organization of food and water supply to the population in the danger zone.
5. Providing medical assistance to victims.

When conducting these activities, you need to know the number of people that need to be found in each house, quarter, district. In the earthquake zone, the prevention of panic and mental reactions of a mass nature is of key importance.

Sanitary losses

Considering the main characteristics of earthquakes , it is necessary to say separately about the damage to the population. In the destruction zone, most people receive various injuries. The possibility of a combined defeat is not excluded. It occurs with the simultaneous destruction of structures, fires, accidents at explosive and chemical objects. The population is often left homeless. At the same time, being in the surviving buildings is dangerous due to the likelihood of repeated shocks. Sewer and plumbing systems, medical facilities are being destroyed. In the absence of basic sanitary and hygienic conditions, the risk of spreading infections increases. The characteristics of earthquake damage depend on the area and strength of the disaster, the level of destruction of buildings, population density, the suddenness of the tragedy and a number of other factors. Most often, people have injuries to the limbs, soft tissue bruises.

Factors of population loss formation

Key circumstances are:

1. Indirect (through the nature of the situation in the disaster site as a whole) and the direct impact on people of the destruction of structures and buildings.
2. The influence of secondary natural factors. These include landslides, avalanches, mudflows, tsunamis, etc.
3. The impact of secondary factors due to human activities. This, in particular, is about fires during the destruction of oil storage facilities, electric networks, gas pipelines, enterprises that have stockpiles of radioactive, chemical and other dangerous compounds.
4. Diseases

Analysis

A study of the causes of injuries in disasters shows that 10% of all injuries were caused by collapses, collapses of roofs and walls, 35% from falling debris, structures, and 55% due to improper behavior of victims caused by panic and fear. Currently, there is no complete and evidence-based information on the specific gravity of heavy, light and moderate damage during earthquakes. If we talk about disasters that have occurred over the past half century on the territory of the Russian Federation, this is primarily due to the fact that most of the people who received minor injuries did not seek help, or pre-medical measures in the disaster area were not recorded. Experts suggest that this applies to a certain part of the population with moderate injuries. A certain proportion of citizens, having received the first medical care, subsequently did not go to medical institutions.

Important point

As international experience shows, if rescuers can enter the disaster area in the first three hours, then they can evacuate up to 90% of the living. After 6 hours, the number of saved can be reduced to 50%. Further, the chances of evacuating the survivors are significantly reduced, and 10 days after the tragedy there is no sense in rescue operations. So, for example, on December 7, 1988, a major earthquake occurred in Armenia. The first groups of rescuers managed to get into the disaster zone only in the evening of December 10. Planned work began only by the 12th.

Classification

Different researchers determine the types of earthquakes and their characteristics in different ways. The most common are classifications according to the magnitude of vibrations and intensity. On the last sign, the characteristics of earthquakes on the Mercalli scale are based . According to the magnitude of the oscillations, the types of disasters were determined in 1935 by Charles Richter. The researcher analyzed the energy that is released in the form of seismic waves during shocks and vibrations. The characteristics of earthquakes on the Mercalli scale are carried out according to external signs.

Table

Consider the external signs of disasters of varying strength.

Existing difficulties

Characteristics of high intensity earthquakes indicate the need for quick and accurate work in a disaster. In particular, we are talking about the timely provision of medical assistance to the victims, the organization of their evacuation, transportation to medical institutions. To implement this task, you need to have reasonable information about the structure and magnitude of the likely losses. Its receipt is considered to be a more complicated issue than predicting the possibility, intensity of a disaster, the direct characterization of earthquakes and their consequences. Meanwhile, the analysis of potential losses is a necessary condition for ensuring the implementation of a set of primary measures. It is worth saying that the ability to predict the number of accidents is significantly lower than the amount of damage.

Medical evacuation measures

The basis of their organization is the characteristic of earthquakes of different intensities. Depending on the strength of the shocks, fluctuations, the degree of destruction, sets of measures are developed to eliminate the consequences and provide assistance to the victims. Equally important are the capabilities of the health care system operating in the disaster area, the availability of staff funds designed to ensure evacuation. When eliminating the consequences of most of the devastating earthquakes in Russia , a phased treatment model is used with transportation of the injured to specialized institutions. It is worth noting that the organization of primary events differs not only in different disasters, but also in different areas within the same disaster zone. This was quite clearly manifested, in particular, during the liquidation of the consequences of the 1948 earthquakes in Ashgabat, 1988 in Armenia and in 1995 on Sakhalin.

Event specifics

The characteristic of high intensity earthquakes indicates the almost instantaneous formation of sanitary losses. In this regard, immediately after the disaster, relief work arises in full. At the initial stage - for several hours - the events are spontaneous. At this stage, mutual and self-help is provided. Depending on the capabilities of contingencies and staff, as well as the conditions in the disaster area, different rates of increasing the intensity of work can be noted. Prior to the emergence of organized assistance, a more or less significant part of the victims are evacuated independently or with the help of other citizens outside the disaster area. This suggests that among the people remaining in the earthquake source, the proportion of those who have moderate to severe injuries is increasing.

The need for preliminary activities

With the most severe earthquakes in terms of health consequences, the capacity of health facilities operating in or near the disaster area may not be sufficient. The large area, the “attachment” of medical institutions to settlements located in earthquake-prone areas is quite far from each other, the shortage or absence of specialized places of a certain profile, as a result of which evacuation is carried out in remote areas, all this requires work to reduce the risk of adverse consequences or a significant deterioration in the health of victims during transportation. For example, during a disaster in Armenia, 87% of people were transported to medical facilities in Yerevan, only 8% remained in district hospitals. During the earthquake in Sakhalin, all injured in need of hospitalization (more than 360 people) arrived in the city of Olkhu. It is located 70 km from the disaster area. Subsequently, a significant part of the victims from the institutions to which they were hospitalized were transferred to other cities.

Conditions for the formation of disaster medicine services

As experience in providing assistance to victims shows, in practice there were no cases when the institution that participated in the liquidation of the consequences carried out only regulated activities of any one kind. Medical and nursing teams and ambulances usually performed some medical procedures. Moreover, in almost all cases, the surgeon worked in medical posts. Employees also carried out a number of emergency measures included in the qualified assistance. All this must be taken into account when forming disaster medicine services. Institutions of departmental or territorial health care that are deployed in the disaster area, regardless of their equipment and staff, as a rule, provide victims with first aid of a medical nature and carry out some activities of a specialized type.

The principles of planning and production of medical evacuation works

In earthquakes, the intensity of which is 5-6 points, it should be borne in mind that:

1. Most of the residents of the disaster area will not be affected and will be able to participate in rescue operations, including providing first aid to other people. The effectiveness of their activities will depend on the quality of preparatory work on the ground.
2. 88-100% of structures will not receive serious damage, and most of the medical facilities will remain operational.
3. Affected and in need of help persons will seek her in the very near future after a disaster.
4. With a 5-point earthquake, a small number of injured people will not need hospitalization, labor-intensive measures to provide medical and qualified medical care, with a 6-point earthquake - about 12.5% ​​will go to medical facilities.
   

Work on the ground at a higher shock intensity

7-8 , , . . , , , 7-10 , 8 – 3-4-. , , - . 7- 4-7 , 8- – 9-10 . 3% . 7- 8- . 13% , 23% - . .

Additionally

Despite the fact that in comparison with the consequences of an 8-point earthquake, the consequences at 9-10 points are worsened by only 15%, and at 11-12 they even decrease by 15-22 and 35-50%, respectively, the conditions for providing medical evacuation events will be more complicated. Thus, only a small number of victims can receive first aid in the manner of mutual and independent rendering of it. Total losses among the population during 9-12-magnitude earthquakes can reach 55-81% of the total number of citizens. Moreover, among them 65-80% of people will have moderate and severe injuries. All these data indicate that the first medical aid will be provided to the main part of the victims only by emergency personnel or citizens who will arrive from other settlements located outside the disaster area.